The quality of gold film is critical to the preparation of Si nanowires by metal-assisted chemical etching(MACE). The introduction of Ti and Cr as a wetting layer on Si substrate can suppress the tendency to form 3-D islands of Au atoms. Hence, high quality Au film with less usage of raw material can be obtained by this method. Further investigations of the Ti and Cr wetting layer on the morphology of etched Si by Au-assisted chemical etching show that: Cr is stable in etching solution and can block the reaction, while Ti reacts rapidly with etching solution and hereby doesn’t prevent the catalyzing etching effect on Si substrate of Au layer. Accordingly, gold film with good quality was prepared by depositing 3nm/20nm Ti/Au with polystyrene(PS) sphere template, then orderly controlled Si nanowires array was prepared through MACE.
